Applied research has played an important role in the Western Gulf Center of Excellence for Vector-Borne Diseases, as the institution spearheads efforts to control mosquitoes, ticks and other vectors of human and zoonotic diseases.
After five years of research, Phillip Kaufman, Ph.D., head of Texas A&M’s entomology department, said the projects laid the foundation for the center and its public health mission. Research conducted by Texas A&M AgriLife Research and Department of Entomology scientists has been instrumental in efforts to develop insect and disease control methods and predictive tools for Texas communities.
“The center has made tremendous strides in its mission of research, awareness and education, but research is fundamental to long-term success in vector control and disease prevention,” Kaufman said. “Science focused on understanding vectors and providing new methods to protect public health is the spearhead of this entire effort.”
Building a research partnership. Outbreaks of viruses such as Dengue, Chikungunya, West Nile, and Zika in parts of the United States have led to the establishment of five Regional Vector-Borne Disease Centers of Excellence.
The Western Gulf Center of Excellence for Vector-Borne Diseases is based at the University of Texas Medical Branch and includes partnerships with AgriLife Research and the Texas A&M AgriLife Extension Service as well as other universities and public health agencies. The Center has four counterparts who represent a five-year, $50 million grant program funded by the Center for Disease Control and Prevention, CDC, designed to strengthen research, education, and awareness efforts aimed at preventing disease. vector-borne.
Kaufman said the College of Agricultural and Life Sciences, Department of Entomology and AgriLife Research have all played important roles in the university’s collective efforts for scientific advancement against vectors and vector-borne diseases. .
“The cooperative and complementary efforts of our scientists for the Western Gulf Center speaks to the overall mission to improve our understanding of vectors like mosquitoes and how we can control them more effectively,” he said. “The past five years have created a solid foundation for future progress in this area that ultimately supports stronger research, education, and outreach in support of regional public health.”
Mosquito control evaluation. Over the past five years, scientists have conducted applied research projects designed to examine mosquito resistance to insecticides and to evaluate statewide vector intervention programs, among other things.
Gabriel Hamer, Ph.D., AgriLife Research entomologist, Bryan-College Station, said much of the research done by Texas A&M scientists is aimed at improving integrated mosquito management in the region. The creation of the center has helped focus research efforts on locally relevant challenges that offer potential for translation into improved public health practice.
Hamer’s work has been instrumental in evaluating mosquito surveillance and control practices in cities and counties scattered across Texas. The collaboration of a local mosquito control program with a university laboratory provides access to additional tools or capabilities that are often not possible in isolation.
He and his team of students and staff have worked with the City of Brownsville, Harris County Public Health, and other state agencies to meet this need.
“Assessing the functioning of vector control tools is often the most overlooked aspect of integrated mosquito management,” he said.
Build a community of practice. Through Centers of Excellence, CDC encourages “communities of practice,” defined as a group of people who share a concern, set of problems, or passion for a topic, and who deepen their knowledge and expertise in interacting on a continuous basis. based.
Supporting the concept through research was a priority, as communities of practice provide a collaborative framework for public health professionals to work with partners in academia and beyond to identify and leverage best practices and related standards. to vector-borne diseases.
“The communities of practice aspect is one of the most exciting parts of our Center of Excellence,” Hamer said. “I think everyone is proud of how the center has boosted communication and collaboration.”
The Center of Excellence’s many participants scattered across multiple universities publish research findings with staff from academic, local, and national health agencies as co-authors. These products are testament to the effective networks that have been developed to reduce the perpetual challenges of siled research activities that are not in touch with local needs, Hamer said.
One of Hamer’s research projects involving numerous local and state partners was a survey of Texas residents in Harris, Tarrant, and Hidalgo counties regarding their acceptance and willingness to pay for mosquito control.
Many city and county vector control agencies are severely underfunded and lack resources for effective integrated mosquito management, and the results of this survey suggest an unmet demand for mosquito control in Texas.
“We started this project when we saw that the area has very few city-wide or county-wide vector control programs funded by local taxes,” he said.
Currently, the average amount of tax funding for vector control in these three counties is 78 cents per person per year, but the survey found that participants were willing to pay $53.15 in annual fees. Participants were also asked which control methods, including adulticides, larvicides, death traps and modified mass mosquito releases, they were willing to support.
The survey found that most participants were overall supportive of all control methods, with the highest support for kill traps and the lowest support for genetically modified mosquitoes. This study was recently published in the CDC’s journal Emerging Infectious Diseases.
Develop disease control and forecasting tools. Other AgriLife Research entomologists have conducted applied research to assess the effectiveness of current control practices or to develop new disease prediction tools.
Patricia Pietrantonio, Ph.D., AgriLife Research Fellow and Professor in the Department of Entomology, worked with Harris County’s Mosquito and Vector Control Division to study mosquito resistance to organophosphates and pyrethroids, both only adulticidal chemicals approved for control applications.
Research has sought to determine the type of molecular resistance mechanisms present and their frequency in known populations of mosquito vectors. A better understanding of the susceptibility of wild mosquito populations to control products will improve decision-making to ensure efficacy and reduce further development of resistance.
The tests determined that two mutations in the pyrethroid target, sodium channel, are associated with resistance in Aedes aegypti populations in Harris County. The work has been published in the journal PLOS
Neglected tropical diseasesFemale mosquitoes of Aedes and Culex species were collected from Harris County and exposed to different pesticides, including malathion and permethrin, to estimate the percentage of resistant mosquitoes. For Culex quinquefasciatus, the main mosquito that transmits West Nile virus in this region, the mutation conferring resistance to pyrethroids is widespread in Harris County. Published research is now guiding control measures in these regions.
The study also identified genotypes within mosquito populations that produce metabolic resistance to traditional pesticides when expressed.
Kevin Myles, Ph.D., Professor, and Zach Adelman, Ph.D., Professor and AgriLife Research Fellow, both in the Department of Entomology, studied how temperature and humidity levels are associated with immune responses from mosquitoes to pathogens to predict the risk of transmission.
This work was accomplished in partnership with Harris County’s Mosquito and Vector Control Division to deploy microhabitat sensors, which then informed the environmental conditions of mosquitoes reared in College Station insectaries. Mosquitoes given different larval conditions, which influence their immune system, were then evaluated for their ability to transmit the Zika virus.
Kaufman said this type of research could help predict outbreaks based on environmental conditions.
“It is important to understand the environmental factors that could fuel an outbreak by different mosquito-borne viruses,” he said. “Using disease prediction tools that adapt to the different microhabitat conditions encountered by mosquitoes that inform transmission risk could be a promising approach.”
Investment fuels innovation, protection. The first five-year round of funded research within the Western Gulf Center encountered some hurdles due to the COVID-19 pandemic, including the suspension of laboratory and field work at times. But Hamer said the center continues to facilitate dialogue between academic and public health partners as they juggle attention to the pandemic alongside vector-borne diseases.
For example, the Texas Department of State Health Services, together with the Western Gulf Center, launched the Texas Tick Working Group in 2019 with quarterly conference calls to discuss tick research and public health priorities. These well-attended videoconferences continued during the pandemic and provided communities of practice that had never existed before regarding the public health threat of ticks in the region.
Hamer hopes that the CDC’s next round of funding for Centers of Excellence in the United States will continue to build on the foundations gained over the past five years and maintain the ability to meet the threats of tomorrow.
“It is an excellent choice for a land-grant university to partner with the Vector-Borne Disease Center of Excellence so that locally relevant applied research is funded to meet regional societal needs,” said he declared. “Partnerships between universities, public health agencies, pest management professionals and industry are all needed to manage the changing threats posed by insect vectors that impact human and animal health.”